Underfeed stoker.



PATENTED DEC. 27, 1904.

E. E. TAYLOR.

UNDERFEED STOKER.

APPLIGATION FILED maze, 1903.

SSHEETS-SHBET 1.

PATBNTBD DEC. 27, 1904.

E. E. TAYLOR,

UNDERFBED STOKER.

APPLICATION FILED monza, 1903.

3 SHEETS-SHEET 2.

No. 778,812.. PATENTE) DEQ. 27, 1904.

RLT/mma.

UNDBRFEED sToKBR.

APPLICATION FILED DEO.26, 1903.

3 SHEETS-SHEET 3y UNITED STATES Patented December 27, 1904.

ELVOOD E. TAYLOR, OF BOSTON, MASSACHUSETTS.

UNDERFEED STOKEF'l SEECIFICATION forming part of Letters Patent No. 778,812, dated December 27, 1904.

Application filed December 26, 1903. Serial No. 186,526.

To (//ZZ 1072/0717/ it may concern:

Be it known that I, ELwooD E. TAYLOR, of Boston, in the county of Suolk and State'of Massachusetts, have invented certain new and useful Improvements in Underfeed Stokers, of which the following is a specification.

This invention relates to mechanical stokers operating' on the underfeed principle; and its objects are to secure certainty and uniformity of action, avoid clogging, decrease the feeding power required, and to simplify and otherwise improve the construction of the stoker, as will more fully hereinafter appear.

ln the preferred embodiment herein selected for illustration the stoker is constructed with a series of retorts located side by side in the same lateral zone--that is, occupying successive positions along a zone which extends crosswise of the direction of feed and having sloping mouths longest in an up-and-down direction and inclined sufliciently to effect a gravity-feed of the ash and superficial burning portions of the fuel to the bottom of the incline, where they accumulate upon an adjustable support, which may be inverted to dump the ashes and elinker. Between the retorts and lianking the same are inclined airboXes receiving compressed air from a fan and provided with renewable twyer-blocks, between which are twyers or air-outlets. The fuel is fed from a hopper onto the back wall of the retort, which is inclined sufficiently to effect a gra vity-feed and is pivotally mounted and oscillated by suitable mechanismfso as to feed the fuel outwardly across the plane of the retort-mouth, both ends of the pivoted retort wall or pusher acting to feed the fuel.

Of the accompanying drawings, Figure 1 represents avertical longitudinal section of a furnace provided with my improved stoker. Fig. Q represents a horizontal section on line Q 2 of Fig. 1 with parts in plan. Fig. 3 represents a front elevation. Fig. L1 represents a detail perspective view illustrating the manner of mounting the renewable twyer-blocks.

The same reference characters indicate the same parts in all the figures.

In the drawings, is the furnace-inclosure, 11 the bridge-wall, and 12 the front wall, provided with firing-opening 13 and door 14 fm; introducing kindling, &c., to start the fire.

15 15 are a series of fuel-feeding retorts longest in an up-and-down direction-that is, parallel to the slopes of their mouths. The sloping plane or imaginary surface including the mouths of these retorts coincides substantially with the location of the twyer-blocks 16, hereinafter referred to, and, as seen-in the drawings, it is inclined to the horizontal or ground plane at an angle in the neighborhood of thirty degrees, thisangle being insufficient to cause the fuel to slide as an avalanche, but being such an angle as will effect a gravityfeed of the ash and superficial portions of the fuel -bed when the fuel feeds outwardly, as hereinafter described. The lower plate or bottom 17 of each retort is inclined upwardly from front to rear, and the front wall or pusher 1S, pivoted at 19 on a horizontal axis. has a general inclination substantially parallel to the plane of the retort-mouth. The fuel is received in a general hopper 20, having branches 21 connecting to the tops of the several retorts and leading onto the pushers 18 thereof. These pushers are oscillated through a small angle by links 22 and cranks 23 on a common shaft Q4, the latter having worm-gear 25 meshing' with worm 26 on vertical shaft 27. It will be noted that the pusher 18 is pivoted intermediate its ends and has pushing portions both above and below its axis, the upper portion being longer, so as to vfeed more fuel from above than from underneath. The hopper 2O is normally in front of the fire door or doors 14, but is hinged at 28 on a horizontal axis, so as to swing outwardly and downwardly to give access to said door.

Between the several retorts and'flanking the two side ones is a' series of inclined airboXes 29, having a thirty-degree slope and connecting underneath, through suitable branches, with an air-trunk 30, supplied with compressed air by a fan-blower 81. These air-boxes are provided with twyers or airoutlets 3Q, directed slaptina'ly across the mouths of the retorts and formed between a 1 seriesof overlapping'twyer-blocks lo. These l blocks are reniovable and renewable, being' i secured to the sides of the air-boxes by a dovex tail construction, as shown, although other i means of securing" may be employed.

Extended along the lower ends of the rel tort-mouths and air-boxes is a dead or unperl forated 'plate 36 to receive the clinkc' and l ashes, said plate being; pivoted on a horizontal axis and oseillated bylinks BTO and levers i 3T. The plate is formed with a segmental cylindrical lip or apron 38, concentric with its axis, so that when said plate is turned in l, an anticlockwise direction to bring' its hori- Zontal face vertical and dump the collected ashes into the ash-pit 3f) the lower part of the i fuel-bed will not drop into the ash-pit. The ashes may therefore be successfully dumped while the furnace is in operation;

The shaft 27 is represented as connected, through worm-gear 0, worm ft2, pulley li", belt 8, and pulley t), with the crank-shaft a3 of a motor, said eraiiik-shaft also connecting', tl'irough pulley -f-f, belt lo, and pulley sie, with the shaft of the fan-blower 31. rfhere- 'foic when the speed of the motor increased or decreased to vary the feed of the fuel the speed of the fan-blower is varied accordingly, and the amount of air supplied will thereifore correspond to the amount of fuel fed.

AIn the operation of the stoker the fuelbodies in the several retorts 1.5 constitute legs of a single'fuel-bed spreading over the mouths of the rctorts, this fuel-bed bui-nine' with the incandescent fuel on top and the coking' fuel underneath and extending` back into the retorts. The fuel-bed receives its support from the walls of the rctorts, and owing' to thel cohesion and arching property of the coking' fuel as it swells during the cokingl process and is fed outwardly by the rettn't-pushers the Vfuel-bed is kept substantially free Yfrom the twyer-faces of the air-box 29 by arching' over them, thereby to a large extent protecting the twyer -bloeks from burning' out. The feed of the ash is a gravity-feed down the slope of the fuel-bed, induced by the outward feed movement of the fuel across` the plane of the retort-mouths. The feed of thee'reen fuel from hopper 2O is an alternation of gravity-feed along the inclined pusher land outward feed produced by said pusher. Arching' of the fuel inthe retorts relieves the pressure on those portions of the fuel in contact with the pusher lrwhen said pusher rctracts, and accordingly a gravity-feed of fuel lakes place from the hopper, this fuel beine' pushed toward the furnace on the inward stroke of the pusher.

My invention to be distinguished Vfrom those Vforms of mechanical stokers employing' lg'rate produced by a movement ol the lgratebars. In my invention there is no `grate or 1 fuel-su i )ort such as em )loved bv an overfeed stoker, the fuel being' .instead supported from the retorts. ',lhe feed of the ash is a gravity-feed induced by the feed of the `green fuel, andthe Afeed of the green fuel is a combined gravity-'feed and positive pusher-produced feed.

l claim--- l. An under-feed n'iechanical stoker comprisingl a retort having' a sloping' mouth long'- est in a direction up and down the slope thereof and inclined suiiieiently to eliect a gravitylfeed of the ash lengthwise thereof, and means for 'feeding' the Vfuel through said retort from the front thereof across the plane of said mouth.

An underfeed mechanical stoker comprising' a retort having a sloping' mouth long'- est in a direction up and down the slope thereof and inclined suliiciently to efi'ect a `gravityfeed of the ash lengthwise thereof, air-feeding' conduits provided with outlets distriluited along,` the two sides of said mouth in the same lateral Zone, air-|'uo1. elling' means connected with said conduits, and means Yfor Yfeeding the fuel through said retort Yfrom the Yfront to the mouth thereof.

3. An underfced mechanical Stoker comprising` a plurality of retorts arranged side by side in the same lateral zone and adapted to support a single fuelbed, airsupplying means at the sides of the several rctorts, and means to feed fuel through said rctorts, said retorts and air-supplying means alternating in a horizontal direction.

fl. An underfeed mechanical stoker comprising' a retort having a movable front wall sufiiciently inclined to effect a -gravity-feed of fuel therealong, said retort being' longest ina direction up and down the slope of said Vfront wall, and means to reciprocate said movable wall.

An underfeed mechanical Stoker comprising a series of air-outlets, means Vfor forming an arch of fuel over said air-outlets, and means for renewing said arch Yfrom the loes thereof, said devices having' a substantial slope hung'itudinally of the arch for the purpose specified.

6. An underfeed n'lechanieal stoker comprising a retort, a pivoted pusher 'forming` a wall thereof and inclined suliiciently to e'fl'cet a gravity-feed of the fuel, and means to oscillate said pusher.

T. An underfeed mechanical stoker comprising' a retort, a pusher therefor pivoted intermediate its ends and having a pusher portion on each side of its pivotal axis, and means to oscillate said pusher.

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8. An underfeed mechanical stolzer ooml In testimony Whereofl have axecl my sigprising a retort, and an inclined pusher therenature 1n presence of two Witnesses. for pivotecl intermediate its ends on a sul stantially horizontal axis and having its larger ELWOOD E TAYLOR' 5 pushing portion above said axis and its smaller Vitnesses:

pushingportion below the same, and means R. M. PIERSON,

to oscillate said pusher. A. C. RATIGAN. 

